Microcontroller vs Microprocessor

Why a tiny chip with memory built in beats a big CPU for simple jobs.

A microprocessor is mainly a CPU. To make a working computer you add separate RAM, storage and peripheral chips around it. A microcontroller (MCU) places the CPU, memory and peripherals such as timers and serial ports on one chip.

The MCU is cheaper, uses less power and needs fewer parts, so it suits appliances, toys and sensors. A microprocessor suits tasks that need an operating system, large memory or heavy computing, such as a phone or a single-board Linux computer.

Rule of thumb: if the job is a handful of inputs and outputs, choose an MCU.